-kəˈsēnē, -ka-, -kȧ-
Usage: usually capitalized C
Etymology: after G.D. Cassini died 1712 French astronomer
: a curve that is the locus of points of the vertex of a triangle whose opposite side is fixed and the product of whose adjacent sides is a constant and that has the equation [( x + a ) 2 + y 2 ] [( x - a ) 2 + y 2 ] - k 4 = 0 where k is the constant and a is one half the length of the fixed side